.backimg {
    height: 420px;
    background: url("../images/banner-guide.jpg") no-repeat;
    background-size: 100%;
}

.product_active::after{
    content: "";
    border-bottom:13px solid #FFFFFF;
    border-left:8px solid transparent;
    border-right:8px solid transparent;
    position: absolute;
    bottom: 0px;
    left: 50%;
    margin-left: -7px;
    margin-top: 30px;
    top: 10px;
}


@media screen and (max-width: 1150px){
    .backimg{
        height: 500px;
        background-size: 100% 100%;
    }
}
